1.) Field of the Invention
The present invention relates to cleaning agent compositions used for gas turbine air compressors. (The cleaning agent compositions of the present invention are applied mainly to the turbine blades of gas turbine air compressor and possibly even to the members contiguous thereto. More particularly, the present invention relates to cleaning agent compositions suitable for the effective removal of the foulants deposited in gas turbine air compressors and the cleaning of the compressors.
2.) Description of the Related Art
The turbine blades installed in a gas turbine air compressor are rotated at a high speed. As a result, contaminants present in the air adhere onto the surfaces of a large number of such turbine blades in a considerable amount. When the contaminants or foulants deposited on the blades are left unremoved, the operational efficiency of the gas turbine air compressor is reduced remarkably. To avoid the inconvenience, it is necessary to periodically clean the surfaces of turbine blades of the gas turbine air compressor to constantly keep the surfaces in a clean state.
The methods for cleaning gas turbine air compressor are described in, for example, "Maintaining Gas Turbine Compressors for High Efficiency" by Scheper et al. [Power Engineering, August 1978, pp. 54-57]and "In-service Cleaning of Powder Units" by Braaten [The Indian and Eastern Engineer, Vol. 124, March 1982, pp. 111-113]. In these pieces of literature, there are described aqueous surfactant solutions as cleaning agents.
Also, in UK Patent Application Laid-Open No. 2,104,541, there is disclosed a cleaning agent composition used for gas turbine engines. In this cleaning agent composition, there are used ethylene glycol monoethyl ether, ethylene glycol monobutyl ether or the like as the solvent component; sodium dioctylsulfosuccinate or the like as the surfactant component; and a corrosion inhibitor. The pH of the aqueous solution of this cleaning agent composition is controlled at 8-12.
Further in Japanese Patent Application Laid-Open No. 234095/1988, there is disclosed a cleaning agent composition used for gas turbine air compressors. In this cleaning agent composition, there are used, as the solvent component, a compound obtained by adding 1-5 moles of ethylene oxide or propylene oxide to an aliphatic alcohol of 1-4 carbon atoms, such as diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether or the like; and, as the surfactant component, nonylphenyl ethoxylate, an ethylene oxide adduct of a higher alcohol or fatty acid, and a polyoxyethylene coconut oil amine.
In cleaning gas turbine air compressors using any of the above cleaning agent compositions of prior art, however, there are various problems. That is, their cleaning powers are insufficient; the compositions remain partially on the turbine blades of compressor after cleaning, which tends to invite the secondary fouling of the turbine blades; and such residual cleaning agent gives adverse effects on the materials of gas turbine unit.
Therefore, the cleaning of gas turbine air compressor is currently conducted generally by stopping the operation of the gas turbine unit, disintegrating 100-200 turbine blades to take out each blade one by one and clean the respective blades by a physical method. (Thorough cleaning of the turbine unit without disintegrating it is virtually impossible.)
The cost incurred for the above cleaning operation and the compensation for the long period of operational suspension are enormous. Hence, the reduction of such cost or compensation is an urgent and most important task for economy improvement in, for example, electric power plants using gas turbines.